diff --git a/.gitignore b/.gitignore
index e10fb58..3993394 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ arch/src
 arch/doorlockd
 arch/*.xz
 arch/BKCA.crt
+gpio-wait
diff --git a/Makefile b/Makefile
index f666d77..de4004b 100644
--- a/Makefile
+++ b/Makefile
@@ -2,19 +2,21 @@ DESTDIR ?= /
 PREFIX ?= /usr
 SYSCONFDIR ?= /etc
 
-all:
+all: gpio-wait
 	sed -i -r -e "s@(^SYSCONFDIR = ').*('$$)@\1$(SYSCONFDIR)\2@" doorlockd
 	sed -i -r -e "s@(^PREFIX = ').*('$$)@\1$(PREFIX)\2@" doorlockd
 
+gpio-wait: gpio-wait.c
+
 install:
 	mkdir -p $(DESTDIR)/$(PREFIX)/bin/
 	mkdir -p $(DESTDIR)/$(PREFIX)/share/
 	mkdir -p $(DESTDIR)/$(SYSCONFDIR)/systemd/system
 	mkdir -p $(DESTDIR)/$(SYSCONFDIR)
 
-	install doorlockd $(DESTDIR)/$(PREFIX)/bin/
+	install doorlockd gpio-wait doorstate $(DESTDIR)/$(PREFIX)/bin/
 	install doorlockd-passwd $(DESTDIR)/$(PREFIX)/bin/
 	install -m 0644 doorlockd.cfg $(DESTDIR)/$(SYSCONFDIR)
-	install -m 0644 doorlockd.service $(DESTDIR)/$(SYSCONFDIR)/systemd/system
+	install -m 0644 doorlockd.service doorstate.service $(DESTDIR)/$(SYSCONFDIR)/systemd/system
 
 	cp -av share/* $(DESTDIR)/$(PREFIX)/share
diff --git a/doorstate b/doorstate
new file mode 100755
index 0000000..1087daa
--- /dev/null
+++ b/doorstate
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+GPIO=22
+
+function publish {
+	mosquitto_pub -r -t kitchen/doorlock/frontdoor/doorstate -m "$1"
+}
+
+if [ "$(id -u)" != "0" ]; then
+	echo "Please run as root!"
+	exit -1
+fi
+
+while true; do
+	gpio-wait /dev/gpiochip0 22
+	ret=$?
+
+	if [ $ret -eq 0 ]; then
+		publish "closed"
+	elif [ $ret -eq 1 ]; then
+		publish "open"
+	fi
+done
diff --git a/doorstate.service b/doorstate.service
new file mode 100644
index 0000000..9d5a5bf
--- /dev/null
+++ b/doorstate.service
@@ -0,0 +1,12 @@
+[Unit]
+Description=Binary Kitchen doorstate service
+After=network.target
+
+[Service]
+User=root
+Group=root
+ExecStart=doorstate
+
+[Install]
+WantedBy=multi-user.target
+
diff --git a/gpio-wait.c b/gpio-wait.c
new file mode 100644
index 0000000..12b8f40
--- /dev/null
+++ b/gpio-wait.c
@@ -0,0 +1,100 @@
+/*
+ * Doorlockd -- Binary Kitchen's smart door opener
+ *
+ * Copyright (c) Binary Kitchen e.V., 2018
+ *
+ * Author: Ralf Ramsauer <ralf@binary-kitchen.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the LICENSE file in the top-level directory.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <linux/gpio.h>
+
+int main(int argc, const char **argv) {
+	int gpiochip_fd, ret;
+	struct gpioevent_request req;
+	struct gpiohandle_data data;
+	struct gpioevent_data event;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s gpiochip pin\n", argv[0]);
+		return -1;
+	}
+
+	gpiochip_fd = open(argv[1], 0);
+	if (gpiochip_fd == -1) {
+		perror("open");
+		return -1;
+	}
+
+	req.lineoffset = atoi(argv[2]);
+	req.handleflags = GPIOHANDLE_REQUEST_INPUT;
+	req.eventflags = GPIOEVENT_REQUEST_RISING_EDGE | GPIOEVENT_REQUEST_FALLING_EDGE;
+	req.consumer_label[0] = 0;
+
+	ret = ioctl(gpiochip_fd, GPIO_GET_LINEEVENT_IOCTL, &req);
+	if (ret == -1) {
+		perror("ioctl");
+		goto gpiochip_out;
+	}
+
+	ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
+	if (ret == -1) {
+		perror("ioctl");
+		goto req_fd_out;
+	}
+
+	printf("Initial Value: %u\n", data.values[0]);
+
+retry:
+	ret = read(req.fd, &event, sizeof(event));
+	if (ret == -1) {
+		if (errno == -EAGAIN) {
+			printf("Nothing available, trying again\n");
+			goto retry;
+		}
+	}
+
+	if (ret != sizeof(event)) {
+		ret = -EIO;
+		goto req_fd_out;
+	}
+
+	switch (event.id) {
+		case GPIOEVENT_EVENT_RISING_EDGE:
+			printf("Detected rising edge\n");
+			ret = 1;
+			break;
+		case GPIOEVENT_EVENT_FALLING_EDGE:
+			printf("Detected falling edge\n");
+			ret = 0;
+			break;
+		default:
+			printf("Unknown event\n");
+			ret = -EIO;
+			
+			break;
+	}
+
+req_fd_out:
+	close(req.fd);
+gpiochip_out:
+	close(gpiochip_fd);
+
+	return ret;
+}